Commutator for dynamo-electric machines.



UNITED STATES PATENT EETCE.

FRANK A. MERRICK, OF JOHNSTOWN, PENNSYLVANIA, ASSIGNOR TO THE LORAINSTEEL COMPANY, OF PENNSYLVANIA.

COMMUTATOR FOR DYNAWlO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 678,964, dated July 23,1901.

Application led November 14, 1900. Serial No. 36,475. (No model.)

To @ZZ whom t may concern:

Be it known that I, FRANK A. MERRICK, of Johnstown,in the county ofCambria and State of Pennsylvania, have invented a new and usefulImprovement in Comm utators for Dynamo-Electric Machines, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, which form a part of this specification.

My invention has relation to certain new and useful improvements incommutators for dynamo-electric machines, and is designed to providemeans of simple and effective character for preventing thecommutator-bars from working loose or buckling under continued use. Iattain this object by providing the spider or support for the bars witha bearing-surface of such character that when they are secured by theend clamps they are put under a bending stress of such character as tosecurely bind them in place.

My invention also consists in the novel construction and combinationof'parts, all as hereinafter described, and pointed out in the appendedclaims.

In the accompanying drawings, illustrating my invention, Figure 1 is alongitudinal section of a portion of a commutator, and Fig. 2 is alongitudinal section of a similar portion of the spider or support withthe bars and clamps removed and showing the center bearing for thecommutators slightly exaggerated in height.

The letter A designates the usual spidersupport for the commutator-barsB, and C designates suitable clamps which engage the shouldered ends ofthe said bars and clamp them in place.

D designates screws which actuate clamping-Wedges E, by means of whichthe end clamps C are drawn down into engagement with the commutator-barsB.

The bearing-surface of the support A is shaped to provide end bearings dfor the bars B and also a central bearing d', which is slightly higherthan the end bearings a. The effect of this slightly-higher centralbearing when the end clamps are tightened is to put the commutator-barsunder a bending stress and bind them firmly in place, so that they donot tend to work loose or buckle or Warp in operation.

The invention is of particular utility in large sizes of commutators andWhere bars of considerable length are employed, but may also be used toadvantage in smaller sizes.

I do not wish to limit myself to the use of my invention in connectionwith the particular form of end clamps which I have illustrated, sinceit is obvious that various forms of these clamps may be employed.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is-

1. In a commutator, a support for the commutator-bars having a raisedcenter bearing therefor, in combination with suitable end clamps.

2. In a commutator, a support for the commutator-bars, having end andcenter bearings for said bars, the center bearing being slightlyelevated with respect to the end bearings, in combination withsuitable'end clamps for the bars.

3. In a commutator, a support for the bars having its peripheral surfaceprovided with a raised central bearing for said bars.

4. In a commutator for dynamo-electric machines, the combination withthe commu- FRANK A. MERRICK.

Witnesses:

CORA G. COX, I-I. W. SMITH.

